This invention is concerned with a mould arrangement for use in a cyclicly operating glassware forming machine, the arrangement comprising a mould comprising a bottom plate defining a bottom portion of a cavity of the mould, and two side portions defining side portions of the cavity, the side portions being movable towards one another into a closed position thereof, in which the side portions engage the bottom plate and one another to co-operate in defining the mould cavity, and away from one another into an open position thereof to allow moulded articles to be removed from the mould, the side portions also defining passages through which cooling air can pass to cool the side portions.
In a glass container manufacturing machine of the so-called "individual section" type, a number of container making units or sections are arranged side by side, are fed with glass from a common source, and feed their output to a common conveyor. Each of these sections has at least one parison mould in which a parison is formed from a gob of molten glass delivered to the mould, and at least one blow mould in which parison are blown to the shape of the container. The blow mould comprises a stationary bottom plate which defines the bottom portion of a cavity of the mould and two side portions defining side portions of the cavity. The two side portions are mounted on supporting arms which are movable to move the side portions towards one another into a closed position in which the side portions engage the bottom plate and each other so that a parison is enclosed in the cavity defined by the side portions and the bottom plate. The arms are also movable to move the side portions away from one another into an open position to allow moulded articles to be removed from the mould.
Since the moulds of an individual section type machine absorb heat from the glass at a rate which is faster than the heat can be dissipated to the surrounding atmosphere without additional cooling, such moulds are supplied with cooling means which cool the mould so that it remains at a substantially constant temperature during successive operations of the machine. Because the sections of an individual section type machine need to be close together, for reasons of glass supply, only very limited space is available around the mould for the provision of cooling means. One solution to this problem is to feed the cooling air through the frame of the machine section to a vertical cooling stack which is provided with nozzles which direct air on to the outside of the mould. This solution, however, has the disadvantage that the arms supporting the side portions of the mould interfere with the flow of the air to the mould and also it is difficult to provide differential cooling around the mould as may be required. Furthermore, such cooling stacks are a source of undesirable noise. In another type of cooling means, the cooling air is supplied through the supporting arms of the side portions of the mould to a chamber around the mould or to passages within the mould. This type has the disadvantage that it requires expensive machining of the arms, to allow both for the movement of the arms and for the flow of the cooling air. Furthermore, as a seal has to be provided between the arm and the side portion of the mould, delays occur in changing moulds.
In the specification of U.S. patent application Ser. No. 527,589 filed Aug. 29, 1983, there is described a mould arrangement in which cooling air can be supplied to side portions of the mould without the cooling air passing through the supporting arms. In this mould arrangement, the passages in each side portion of the mould each have an entrance in a bottom surface of that side portion and the arrangement also comprises a plenum chamber and air supply means arranged to supply mould cooling air to the plenum chamber for a predetermined period in each cycle of operation of the machine during which the side portions are in their closed position, the plenum chamber extending beneath the side portions and having exits which, when the side portions are in their closed position, communicate with the entrances of the passages so that air can leave the plenum chamber and pass through the passages.
In the mould arrangement described in the aforementioned specification, the bottom plate of the mould is mounted on a bottom plate mechanism which is mounted for vertical adjustment on a supporting frame of the machine and the plenum chamber is also mounted on the bottom plate mechanism. The bottom plate mechanism is mounted on a slideway in a vertically extending recess of the machine and the plenum chamber extends horizontally over the frame and has an entrance which receives the air supplied by the air supply means through a telescopic connection to the interior of the frame.
While the arrangement described in the aforementioned specification is satisfactory in many respects, it cannot readily be adapted to operate in the "triple gob" mode in which each section of the machine moulds three containers simultaneously; this is because there are only two air passages in the section frame which can be utilised for supplying air to the plenum chambers. Also, because the plenum chamber extends over the section frame, the height of containers which can be moulded in the machine is limited.
It is an object of the present invention to provide a mould arrangement in which cooling air can be supplied to side portions of the mould without the cooling air passing through the supporting arms and in which the above mentioned disadvantages are overcome.